Schmidt Bernhard, Czosnyka Marek, Klingelhöfer Jürgen
Department of Neurology, Chemnitz Medical Centre, Pembaurstr 14a, 81243, München, Germany.
Eur J Ultrasound. 2002 Nov;16(1-2):37-45. doi: 10.1016/s0929-8266(02)00044-7.
Until now the assessment of intracranial pressure (ICP) requires invasive methods. A previously introduced mathematical model allowed the non-invasive estimation of ICP (nICP) from arterial blood pressure (ABP) and blood flow velocity (FV). In various studies we have investigated the accuracy of this method and possible clinical applications.
Selected hemodynamic parameters, calculated from the cerebral blood FV and the ABP curves, were used to express the relationship between ABP input and ICP output by linear transformation rules. In several clinical studies the accuracy and possible benefits of this method of non-invasive ICP (nICP) assessment were investigated. ASSESSMENT OF ICP PLATEAU WAVES: In 17 severely head injured patients we verified this model by comparison of nICP and measured ICP during generation of plateau waves, recorded in seven of these patients. In all simulations plateau elevations of ICP were well replicated. The correlation coefficient between increase of nICP and real ICP was R=0.98; P<0.001. LUMBAR INFUSION TESTS: Twenty one hydrocephalic patients were studied. Parallel increases in real ICP and nICP during lumbar infusion tests were evidently visible. Resistance of cerebrospinal fluid outflow (Rcsf) was computed using nICP and compared with Rcsf computed from real ICP. The mean error between real and non-invasive Rcsf was 4.1+/-2.2 mmHg min/ml. CEREBRAL AUTOREGULATION: One hundred and forty five patients were studied after severe head injuries. The state of autoregulation was assessed by moving correlation of cerebral perfusion pressure (CPP=ABP-ICP) and FV (Mx index). nICP instead of ICP was used to continuously estimate the state of autoregulation and to dynamically adapt the nICP procedure to this state. A median error between ICP and nICP of 6.0 mmHg was observed. Directly and non-invasively assessed Mx indices correlated highly significantly (R=0.9; P<0.001).
The results demonstrate that the nICP assessment model constitutes a reliable method to monitor ICP and may therefore provide various useful clinical applications.
迄今为止，颅内压（ICP）的评估需要采用侵入性方法。此前引入的一个数学模型能够根据动脉血压（ABP）和血流速度（FV）对ICP进行非侵入性估计（nICP）。在多项研究中，我们对该方法的准确性及可能的临床应用进行了调查。
从脑血流FV和ABP曲线计算得出的选定血流动力学参数，通过线性变换规则来表达ABP输入与ICP输出之间的关系。在多项临床研究中，对这种非侵入性ICP（nICP）评估方法的准确性及可能的益处进行了调查。ICP高原波评估：在17例重度颅脑损伤患者中，我们通过比较nICP与7例患者记录到的高原波产生期间测量的ICP来验证该模型。在所有模拟中，ICP的高原升高均得到了很好的复制。nICP升高与实际ICP之间的相关系数为R = 0.98；P < 0.001。腰椎灌注试验：对21例脑积水患者进行了研究。在腰椎灌注试验期间，实际ICP和nICP明显平行升高。使用nICP计算脑脊液流出阻力（Rcsf），并与根据实际ICP计算的Rcsf进行比较。实际Rcsf与非侵入性Rcsf之间的平均误差为4.1±2.2 mmHg·min/ml。脑自动调节：对145例重度颅脑损伤患者进行了研究。通过脑灌注压（CPP = ABP - ICP）与FV的移动相关性（Mx指数）评估自动调节状态。使用nICP而非ICP来持续估计自动调节状态，并根据该状态动态调整nICP程序。观察到ICP与nICP之间的中位数误差为6.0 mmHg。直接和非侵入性评估的Mx指数高度显著相关（R = 0.9；P < 0.001）。
结果表明，nICP评估模型是一种监测ICP的可靠方法，因此可能提供各种有用的临床应用。
